Question

How would you balance: $Ba + {H_2}O \to Ba{\left( {OH} \right)_2} + {H_2}$?

Answer 1

Hint: Balancing a reaction means equaling all the elements present on the reactant side and product side. One can try to equate all elements present in it by a common number which can make the number of atoms of each element on both sides equal. One can use even a fraction number for balancing the equation.

Complete step by step answer:
1) First of all, we will try to analyze the given unbalanced chemical reaction and find out the fractions which can give us the balanced reaction equation as below,
$Ba + {H_2}O \to Ba{\left( {OH} \right)_2} + {H_2}$
2) Now in the above reaction equation, let's first find out which element has the highest number of atoms on any one side. The element hydrogen has four atoms in total on the product side.
3) Now on the reactant side there are only two hydrogen atoms present which means we need to multiply the water molecule by two and let us see if that can balance the reaction as below,
$Ba + 2{H_2}O \to Ba{\left( {OH} \right)_2} + {H_2}$
In the above reaction, if we analyze both sides, we can say that there is only one atom of Barium on the reactant side and only one atom of barium on the product side. There are four atoms of hydrogen and two atoms of oxygen on the reactant side and there are a total of four atoms of hydrogen and two atoms of oxygen. This means the total number of atoms of each element on the reactant side is equal to the total number of atoms of each element on the product side which denotes the above reaction as a balanced chemical reaction.
4) Therefore, the balanced chemical reaction is as below,
$Ba + 2{H_2}O \to Ba{\left( {OH} \right)_2} + {H_2}$

Note:
While balancing the reaction one should always remember to use the minimum coefficient of numbers for elements. A balanced reaction is proof of the law of conservation of mass where it can be elaborated as mass cannot be created nor be destroyed in a chemical reaction.